GRS 1915+105 multiwavelength campaign in 2000 April Yoshihiro Ueda Institute of Space and Astronautical Science As informed earlier, the multiwavelentgh campaign of the microquaser GRS 1915+105 with ASCA, CGRO/OSSE and other observatories will start from April 17 and last till April 25. Attached below are observation programs currently fixed. We again encourage whoever interested to make ground observations in IR and radio during this period. Both of photometic and spectroscopic observations would be useful. For details of the campaign and information of exact ASCA pointing intervals, please contact Yoshihiro Ueda (ueda@astro.isas.ac.jp). ---- GRS 1915+105 observation programs as of April 17 9:00 ---- ALL times are given in UT. 1) X-ray ASCA: from 4/17 13:35 to 4/25 12:00 RXTE: 4/17 12:50-13:42, 14:25-15:18 4/22 and 4/23 BeppoSAX: 4/22 and 4/23 2) Gamma-ray OSSE/CGRO: from 4/18 to 4/25 3) simultaneous VLA and IR (ESO-NTT) Felix Mirabel et al 4/17 12:56-15:26 4/22 08:08-13:07 4/23 07:34-11:03 4) photometric monitoring in K-band at 1.2-m Calar Alto telescope Alberto Castro Tirad et al from 4/18 to 4/25 0:00-5:30 (every day) 5) Nobeyama Millimeter Array (3 mm) Kotaro Kohno et al 4/16 17:05-24:00 4/17 17:05-24:00